Nonfunctioning pituitary adenomas in pediatric and adolescent patients: a clinical analysis of a series of 14 patients.

PURPOSE: Nonfunctional pituitary adenomas (NFPAs) in pediatric and adolescent age are extremely rare. This study aimed to report a series of 14 pediatric and adolescent NFPAs to assist in its clinical management. METHODS: A total of 14 consecutive patients pathologically diagnosed with NFPAs (age ≤ 20 years) were retrospectively examined, and the clinical data were analyzed. RESULTS: NFPA is uncommon in pediatric and adolescent patients (0.4%). The most common clinical symptoms were a headache (6/14, 42.9%) and visual loss (4/14, 28.6%). Ten patients (71.4%) had preoperative hypopituitarism. All patients were diagnosed with macroadenoma including 8 (57.1%) invasive tumors, and the average tumor diameter was 2.8 cm. All patients underwent transsphenoidal surgery, and a near-total resection was achieved in nine (64.3%) patients. Postoperative visual acuity improved in three patients (75%). The results of immunohistochemistry showed 6 silent plurihormonal adenomas (42.9%), 3 null cell adenomas (21.4%), 3 silent lactotroph adenomas (21.4%), 1 silent gonadotroph adenoma (7.1%) and 1 silent corticotroph adenoma (7.1%). The mean follow-up was 54.8 months, and five patients had tumor recurrence. Tumors with Ki-67 ≧ 2% (28.6%) showed higher recurrence rate than those with lower index (P = 0.001). Two patients received secondary surgery and radiation for recurrent tumors suffered from panhypopituitarism. CONCLUSION: Pediatric and adolescent NFPA is clinically rare, and shows potential invasiveness. The silent plurihormonal adenoma is the most frequent phenotype. Transsphenoidal surgery is as safe and effective as in adults. However, individualized care and teamwork of neurosurgeons, pediatricians, endocrinologists, and radiation oncologists are important, especially for recurrent diseases.

Comparative analysis of intracranial meningiomas in patients younger than 40 years.

PURPOSE: Intracranial meningiomas are relatively rare in young adults, and their specific clinical features remain unclear. The authors analyzed the clinical characteristics of intracranial meningioma in patients younger than 40 years. METHODS: Consecutive patients younger than 40 years with meningioma (n = 223) who underwent surgical treatment at our hospital from 2010 to 2018 were retrospectively reviewed. The study cases was further divided into a younger group (≤ 30 years old; n = 63) and an older group (31-40 years old; n = 160). The clinical information, radiological characteristics, intraoperative findings, and pathological outcomes were extracted from the patients' records and statistically analyzed. RESULTS: Intracranial meningioma is uncommon in patients younger than 40 years (8.6%). The study group's most common symptoms at presentation were headaches (46.7%), visual impairment (27.8%), limb weakness (20.6%), and epilepsy (13.5%). The mean tumor size was larger (51.47 ± 50.36 cm3) in the younger group than in the older group (22.94 ± 27.20 cm3). According to multivariate analyses, young age was an independent predictor of large tumor size, and large tumor size was significantly associated with peritumoral brain edema and intraoperative blood loss. CONCLUSION: Intracranial meningiomas in younger adult patients may have special complexity and perioperative risk due to large tumor sizes. Therefore, individualized treatment strategy is recommended, and the appropriate caution should be taken during surgery.

Capacity and delay estimation for roundabouts using conflict theory.

To estimate the capacity of roundabouts more accurately, the priority rank of each stream is determined through the classification technique given in the Highway Capacity Manual 2010 (HCM2010), which is based on macroscopical analysis of the relationship between entry flow and circulating flow. Then a conflict matrix is established using the additive conflict flow method and by considering the impacts of traffic characteristics and limited priority with high volume. Correspondingly, the conflict relationships of streams are built using probability theory. Furthermore, the entry capacity model of roundabouts is built, and sensitivity analysis is conducted on the model parameters. Finally, the entrance delay model is derived using queuing theory, and the proposed capacity model is compared with the model proposed by Wu and that in the HCM2010. The results show that the capacity calculated by the proposed model is lower than the others for an A-type roundabout, while it is basically consistent with the estimated values from HCM2010 for a B-type roundabout.

A Survey of Needle Steering Approaches in Minimally Invasive Surgery.

In virtue of a curved insertion path inside tissues, needle steering techniques have revealed the potential with the assistance of medical robots and images. The superiority of this technique has been preliminarily verified with several maneuvers: target realignment, obstacle circumvention, and multi-target access. However, the momentum of needle steering approaches in the past decade leads to an open question-"How to choose an applicable needle steering approach for a specific clinical application?" This survey discusses this question in terms of design choices and clinical considerations, respectively. In view of design choices, this survey proposes a hierarchical taxonomy of current needle steering approaches. Needle steering approaches of different manipulations and designs are classified to systematically review the design choices and their influences on clinical treatments. In view of clinical consideration, this survey discusses the steerability and acceptability of the current needle steering approaches. On this basis, the pros and cons of the current needle steering approaches are weighed and their suitable applications are summarized. At last, this survey concluded with an outlook of the needle steering techniques, including the potential clinical applications and future developments in mechanical design.

A Comparison in Travel Characteristics of Bike-Sharing between College Students and Office Workers Based on Theory of Planned Behavior.

As an important component of bike-sharing (BS) users, the travel behavior of college students and office workers is important to the promotion of BS within Chinese cities. To explore the influencing factors for the behavioral intentions of BS, this paper makes a different analysis between the two groups. Based on the theory of planned behavior, and using environmental awareness as an extended variable, a BS travel intention model was developed. A total of 676 valid questionnaires were collected and analyzed from college students and office workers in Zhengzhou. The results indicate that attitude, subjective norms, perceived behavior control, and environmental awareness have a positive impact on the behavioral intentions of BS. However, the influence degree of each variable is different between the two groups. Perceived behavior control, including travel time, travel cost, and cycling difficulty, has the greatest impact on BS behavioral intention for college students. Meanwhile, subjective norms, including policy and media publicity, has the most significant impact on BS behavioral intention for office workers. The impact of environmental awareness on college students' use of BS is higher than that of office workers. We also found that undergraduates use BS more frequently than postgraduates. The findings provide the clear influence factors on behavioral intentions of BS between college students and office workers, that can help policy optimization in terms of bike-sharing systems, giving some suggestion for an approach devoted to deepen the individual-context interactions.

Coexistence of meningioma and other intracranial benign tumors in non-neurofibromatosis type 2 patients: A case report and review of literature.

BACKGROUND: The coexistence of meningioma and other intracranial primary benign tumors is rare, especially in non-neurofibromatosis type 2, and there is limited guidance for the management of such patients. Here, we report a series of 5 patients with concomitant meningioma and other intracranial benign tumors, including subependymoma and pituitary adenoma. CASE SUMMARY: Five non-neurofibromatosis type 2 patients with simultaneous occurrence of meningioma and other intracranial benign tumors were retrospectively reviewed. The patients had no history of previous irradiation. The clinical features, pre- and postoperative imaging, surgical procedure and pathological findings were extracted from electronic medical records. There were 4 female patients (80%) and 1 male patient (20%). The mean age was 42.8 years (range: 29-52 years). The coexisting tumors included subependymoma in 1 case (20%) and pituitary adenoma in 4 cases (80%). The most common clinical symptom was headache (3/5, 60%). Four patients (80%) underwent craniotomy. One patient (20%) underwent transsphenoidal surgery followed by transcranial operation. All tumor diagnoses were confirmed by histopathological examination. The mean follow-up was 38.8 mo (range: 23-96 mo), and all 5 patients were in a stable condition at the last follow-up. CONCLUSION: The simultaneous occurrence of meningioma and other intracranial benign tumors is a rare clinical event. Histological examination is necessary for the accurate diagnosis. Neurosurgeons should select the appropriate surgical strategy according to the clinical features of each patient, which may provide a more favorable prognosis for individual patients.